Groth Sabrina, Budke Christoph, Neugart Susanne, Ackermann Sofia, Kappenstein Fenja-Sarah, Daum Diemo, Rohn Sascha
Hamburg School of Food Science, Institute of Food Chemistry, University of Hamburg, Grindelallee 117, 20146 Hamburg, Germany.
Department of Plant Nutrition, Osnabrück University of Applied Sciences, 49090 Osnabrück, Germany.
Antioxidants (Basel). 2020 Feb 24;9(2):187. doi: 10.3390/antiox9020187.
Biofortified apples seem to be a suitable produce. In this study, different selenium forms and application levels were applied to the two apple varieties 'Golden Delicious' and 'Jonagold', grown in the years 2017 and 2018 in order to increase the selenium uptake within a typical Western diet. It was shown that the biofortification, which was performed as a foliar application implemented in usual calcium fertilization, led to significantly increased selenium contents in the fruits. Furthermore, biofortification affected the total phenolic content (TPC), the polyphenol oxidase activity (PPO), as well as the antioxidant activity (AOA), the latter measured with the two well-known assays Trolox Equivalent Antioxidant Capacity Assay (TEAC) and Oxygen Radical Absorbance Capacity Assays (ORAC). The varying selenium forms and application levels showed a differing influence on the parameters mentioned before. Higher fertilizer levels resulted in higher selenium accumulation. It was found that PPO activity fluctuates less in biofortified apples. With regard to TPC, selenate led to higher amounts when compared to the untreated controls and selenite resulted in lower TPC. AOA analysis showed no clear tendencies as a result of the selenium biofortification. In the case of 'Jonagold', a higher AOA was generally measured when being biofortified, whereas, in the case of 'Golden Delicious', only one form of application led to higher AOA. Additionally, differences in the amount of major phenolic compounds, measured with High Performance Liquid Chromatography Mass Spectrometry (HPLC-DAD-ESI-MS), were observed, depending on the conditions of the biofortification and the variety.
生物强化苹果似乎是一种合适的农产品。在本研究中，将不同形态的硒及其施用水平应用于“金冠”和“乔纳金”这两个苹果品种，它们于2017年和2018年种植，目的是在典型的西方饮食中增加硒的摄入量。结果表明，作为在常规钙施肥中进行的叶面喷施的生物强化措施，使果实中的硒含量显著增加。此外，生物强化影响了总酚含量（TPC）、多酚氧化酶活性（PPO）以及抗氧化活性（AOA），后者通过两种著名的检测方法——特洛克斯等效抗氧化能力检测法（TEAC）和氧自由基吸收能力检测法（ORAC）进行测定。不同形态的硒及其施用水平对上述参数有不同的影响。较高的施肥水平导致更高的硒积累。研究发现，生物强化苹果中PPO活性的波动较小。关于TPC，与未处理的对照相比，硒酸盐导致含量更高，而亚硒酸盐导致TPC含量更低。AOA分析表明，硒生物强化没有明显的趋势。在“乔纳金”的情况下，生物强化时通常测得较高的AOA，而在“金冠”的情况下，只有一种施用形式导致较高的AOA。此外，根据生物强化条件和品种的不同，通过高效液相色谱-二极管阵列-电喷雾电离质谱联用仪（HPLC-DAD-ESI-MS）测定的主要酚类化合物含量也存在差异。
